Carbon-rod contact for arc lamps



(No Model.)

0. MoNELLIS. CARBON ROD CONTACT FOR ARC LAMPS.

No. 477,219. Patented June 21, 1892.

UNITED STATES PATENT OFFICE.

CHARLES MONELLIS, OF CHICAGO, ILLINOIS.

CARBON-ROD CONTACT FOR ARC LAMPS.

SPECIFICATION forming part of Letters Patent N 0. 47 7,219, dated June21, 1892.

Application filed January 26, 1892. Serial No. 419,270- (No model.)

T on whom it may concern:

Be it known that 1, CHARLES MCNELLIS, a citizen of the United States,residing at Ohicage, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Carbon-Rod ContactDevices, (Case No. 1,) of which the following is a full, clear, concise,and exact description, reference being had to the accompanying drawings,forming a part of this specification.

My invention relates to electric lamps; and its object is to improve themethod of making contact between the frame of the lamp and thecarbon-rod.

A further object is to so construct the contact-brush and the socketwhich holds it in such manner that the contact-brush can be removedreadily and a new one substituted in place thereof whenever desired.

A further object is to provide a close-fitting ring surrounding thecarbon-rod, of such shape as to ofler as little frictional resistance aspossible to the movement of the carbonrod, which ring may be removed andreplaced upon occasion.

Heretofore the part of the lamp of which my invention is an improvementhas been made in one piece, the contact-brush having been soldered tothe interior of the tube through which the carbon-rod slides and theclose-fitting ring having been soldered to the tube. The consequence ofthis construction has been considerable labor in the first making of thedevice, which is obviated by the construction which I have invented,while the necessity of discarding the entire piece, ineluding tube,brush-contact, and ring, in case of the destruction of anypart isobviated. In the device of my invention any one of these parts may bereplaced without discarding the other parts, thus resulting in a savingin expense and also in a saving of time and labor in making the change.

Aclear understanding of my invention will be obtained by reference tothe accompanying drawings, in which- Figure 1 shows the device ofmyinvention, partly in section, with the parts thereof in a separatedcondition. Fig. 2 shows the device of my invention, partly in section,with the parts thereof together as they would be normally when in placein the lamp. Fig. 3

shows the device of my invention in elevation,

as it would appear when in place in a lamp, with the base of the casesurrounding the works of the lamp cut away. Fig. 4 shows the sideelevation of a contact-brush. Fig. 5 shows an end view of acontact-brush. Fig. 6 shows the close-fitting ring and the end of thecarbon -rod which passes through the same.

Similar letters of reference refer to similar parts of the devicethroughout the different views.

The base a of the case containing the works of the lamp receive in ahole threaded for this purpose the device of my invention. I preferablymake my device of the same size and with the same description of threadthat have been in use heretofore, so that my improved device may besubstituted for the old ones without inconvenience. The tube 1) has outupon it two threads. One 0 is adapted to fit the thread in the case ofthe lamp-works before described. The other dis adapted to receive thethread of the cap or nut e. In the end of the tube 1) the annular recessf is provided for the purpose of affording a seat for the ring g and forthe upset end of the contact-brush h. The ring g has its interiorsurface rounded and smoothed, so as to fit the carbon-rod i closely, andthus prevent oscillation of the rod and also prevent the admission ofdust and dirt into the works of the lamp. This ring fits into the seat fof the tube b, and the screw-cap Q has a sufficiently large internaldiameter to pass over the ring when it is screwed upon the thread (1.Upon the lower side of the screw-cap 6 there is the inwardly-proj ectingannular lip 7o, leaving an opening larger than the inside diameter ofthe ring g, but smaller than the outside diameter of said ring, wherebythe ring is held firmly in the seat f. The ring may be cut away atZsufficiently to allow the screw-head m on the side of the carbon-rod topass through.

The contact-brush n I make, preferably, of thin phosphor-bronze sheet;but any other metal which has the requisite flexibility and resiliencymay be used instead of phosphorbronze. This contact-brush may be stampedfrom a sheet, after which it maybe formed in the shape shown mostclearly in Figs. 4 and 5. The curvature of the arms 0 0 0, of which Ipreferably have siX, presses the ends against the interior of the tubeand bears against the carbon-rod as it slides through said tube. The endof the contact-brush shown in Fig. 5 forms the segment of a circle,preferably somewhat larger normally than the interior of the tube,whereby when the contact-brush is inserted in the tube it will tend tospring apart, and thus press against the interior of the tube.

An obvious modification of my device would consist in making the ringgintegral with the screw-cap 6; but I preferably make it separate, asherein described.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a device for making contact with the carbon-rod of an electriclamp, the combination of the tube 1), detachably secured to the floor ofthe lamp, the contact-brushn, the ring g, adapted to press the flange ofsaid contactbrush against the end of said tube, and the screw-cap 0,adapted to hold said ring and contact-brush detachably in place,substantially as described.

2. A device for making contact with the carbon-rod of an electric lamp,consisting of a contact-brush of comb-shaped metal curved so as to enterthe tube through which the earbon-rod passes, said comb-shaped piece ofmetal having its teeth curved and having a flange adapted to rest uponthe end of said tube, in combination with a cap adapted to be screwedupon the end of said tube and to press upon the flange of saidcontact-brush, whereby said contact-brush is detachably held in place insaid tube, substantially as described.

In witness whercof I hereunto subscribe my name this 30th day ofDecember, A. D. 1891.

CHARLES MONELLIS. Witnesses:

GEORGE P. BARTON, GEORGE L. CRAGG.

